The top & bottom plane are VCC & GND, so it's where i switch between layers to allow the fill to pass by those traces
and this is not the final layout. it was a first go at seeing of something like that would work . and also to get some feedback of what you guys think .

I like this idea. There are several cases where I would like to have something between blue pill (103C8) and blue pad (407VE). When and how I can buy one. Initially, the price is not critical for me.

Same here, as i'm learning how to design boards, it's fun to see what would be possible in the range of boards i'd actually like. i love the bluepill/maple mini size, and i'm wondering if we can't pack more power into that size. But i'm still pretty new at this, so maybe after building & using those boards, i'll discover why they're not being made ^^'.
i'm also wondering what other's capabilities are on this forum, if it just ends with a nice design for this, will people have them produced at one of the boardhouses & assemble a few themselves? (it's easier than i used to think .)
it's a fun road to go down, making your own boards, and seeing the f4 bluepill thread, i'm wondering where this will lead .

and i also like the feedback on the design (like the voltage regulator)
aliexpress can be *very* frustrating in finding good parts >_<...

The problem with the original design is not the power dissipated itself, but the package type which has got a large thermal resistance so it will smoke at Iout >200mA. A sot-223 or sot-89 or dpack is a better choice, but still the power must be dissipated somewhere.

If you chase a small size and large currents and less heat then the only solution is a switcher.. The switcher is more complex and adds noise which is not easy to filter.

There was a reference to 100 pin STMH743 as the next step after F4. Here are some reference points of prices:
1. STM32H743ZI Nucleo board
- I got mine today and paid $23 at Mouser
- After the purchase, I have seen the prices as low as $19
2. STM32H743ZI chip (144 pin)
- Directly from ST for $8.90 (in lots of 10,000)